| 摘要 |
In the present invention a method to address voltage drop effect in the path based timing analysis for multi-phase sequential circuit is proposed. In calculating the new delay of the gate along the specified path the fact that stored discrete arrival times with respect to different clock phases at each node is used to determine a set of gates that can have transitions overlapping with that of the said gate. Furthermore, the said set is reduced by the logic verification step. Two step approach is adopted, the first is to evaluate the power currents for the said reduced set of gates by using pre-characterized timing library, then use these currents to calculate new VDD of the said gate along the path and obtain new delay for this gate. Some cell may have several internal transitions, the process of modeling power currents in terms of several triangles is discussed.
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